JPH048656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field This invention relates to improvements in vibration isolators.

Prior Art A conventional vibration isolator is shown in FIG. 1, for example.

In the figure, 1 indicates a telescopic attenuator, which can be a conventionally known shock absorber. In this example, the attenuator 1 includes a cylinder 1a,
The cylinder 1a includes a piston (not shown) that divides the inside of the cylinder 1a into two liquid chambers, an orifice and a valve (also not shown) provided on the piston, and a piston rod 1b fixed to the piston.

Here, the piston rod 1b is fixed to a bottom wall 2a of a bottomed cylindrical member 2 surrounding it, and the cylinder 1a is connected to an axle side member by an eye provided at its lower end. The cylinder 1a and the bottomed cylindrical member 2 have one end connected to the cylinder 1a.
The cylinder 1a, the bottomed cylindrical member 2, and the cylindrical cylindrical member 2 are connected to the outer periphery of the cylinder 1a, and the other end thereof is connected to the outer periphery of the bottomed cylindrical member 2 by a cylindrical cylindrical membrane 3 that is airtightly fixed to the outer periphery of the cylinder 1a, the bottomed cylindrical member 2, and the cylindrical cylindrical member 2. The membrane 3 constitutes an air chamber 4 as an example of a gas chamber.

Further, the bottomed cylindrical member 2 has a shaft portion 5 coaxially provided with the piston rod 1b on the outside of the bottom wall 2a.
It is attached to the vehicle body by passing through and connecting to a bracket 6, which is an example of a vehicle body side member, and by interposing a mount rubber 7 in the connecting portion.

According to such a vibration isolator, by supplying and discharging compressed air to the air chamber 4, the vehicle height is adjusted depending on the magnitude of the load acting on the vehicle body, and the load is also transmitted to the vibration isolator. Low-frequency, small-amplitude vibrations and large-amplitude vibrations are absorbed by the fluid flow resistance within the damper and the volume change of the air within the air chamber. However, the telescope-type attenuator 1 generally has low flow resistance of the liquid sealed therein,
1a, the piston, and other inertial resistance, it is not possible to effectively absorb high-frequency, small-amplitude vibrations such as when a car drives on a gravel road, and the remaining unabsorbed vibrations are directly transmitted from the cylinder 1a. It is known that this is transmitted to the piston rod 1b.

For this reason, in the above-mentioned conventional technology, in order to insulate such residual vibrations from the vehicle body, the vibration isolator is attached to the vehicle body side via the mount rubber 7, but the mount rubber 7 is attached to the air chamber. The spring constant must be set large due to the need to support the pressure and the need to dampen the sudden and large thrusting motion transmitted from the axle side.
Therefore, there has been a problem in that the residual vibrations as described above are transmitted to the vehicle body side without being substantially attenuated.

Therefore, as another conventional technique proposed for the purpose of solving this problem of the conventional technique,
There is one disclosed in Publication No. 58-30507. As shown in FIG.
The piston rod 1b is passed through the inward flange 2b and the piston rod 1b provided on the bottom wall 2a.
are airtightly connected by a bush-shaped elastic body 8 having a smaller spring constant than the elastic body 7, and by allowing the relative displacement of the piston rod 1b with respect to the bottomed cylindrical member 2 by the elastic body 8. , to insulate the vibrations of the piston rod 1b from the vehicle body.

However, the bush-like elastic body 8 here
Since it also functions as a sealing material for the air chamber 4, it has a durability problem in that it is difficult to prevent it from peeling off from the piston rod 1b and the inward flange 2b over a long period of time. , especially piston rod 1b
The spring properties of the elastic body 8, which preferably has a low spring constant in the axial direction and a high spring constant in the radial direction, are significantly restricted due to its sealing function,
As a result, it is not possible to effectively allow the movement of the piston rod 1b in the axial direction, and the rocking movement of the piston rod 1b and thus the damper cannot be sufficiently restrained, and the cylinder 1a or the cylindrical sheathing membrane cannot be sufficiently restrained. 3 collided with the bottomed cylindrical member 2.

In addition, all of these conventional techniques have the problem of not being able to effectively absorb the angular movement about the axis transmitted from the cylinder 1a to the bottomed cylindrical member 2.

OBJECTS OF THE INVENTION The present invention provides a vibration isolator that advantageously solves the problems of the prior art.

Structure of the Invention The vibration isolating device of the present invention particularly provides a relatively small axial relative movement of the piston rod with respect to the bottomed cylindrical member between the piston rod and the piston rod within the bottomed cylindrical member surrounding the piston rod of the damper. A permissible elastic member is arranged, and a mounting bracket is connected to the outer periphery of the bottomed cylindrical member via a cushioning material.

The elastic member here does not need to exhibit a sealing function at all because it is disposed within the bottomed cylindrical member, and the spring constants in the piston rod direction and in the radial direction of the piston rod can be adjusted as required. Since the vibration isolating device of the present invention can be selected as appropriate, the vibration isolating device of the present invention can sufficiently insulate the movement of the piston rod, or in some cases the bottomed cylindrical member, in its axial direction with respect to the vehicle body, and can also prevent the vibration of the damper. Appropriately restrain movement. Furthermore, the cushioning material absorbs the angular motion of the bottomed cylinder member and the damper about their axes, effectively preventing transmission of the angular motion to the vehicle body, and attenuates the above-mentioned rocking motion by restraining it. The rocking motion transmitted from the container to the bottomed cylindrical member can be sufficiently insulated from the vehicle body.

Example This invention will be explained below based on the drawings.

FIG. 3 is a partial sectional view showing one embodiment of the present invention, and in the figure, similar parts to those described in FIGS. 1 and 2 are designated by the same numbers.

The bottomed cylindrical member 2 here has a reduced diameter part 2c at its upper end, and inside this reduced diameter part 2c, the tip of the piston rod 1b and the inner surface of the bottomed cylindrical member 2 surrounding it are covered with rubber. , are connected by an elastic member 11 made of a rubber-like elastic body, foamed resin, or the like. This elastic member 11 is provided in order to sufficiently prevent the transmission of vibration from the piston rod 1b to the bottomed cylindrical member 2 when the input side of the vibration is the damper 1, and when the input side is the bottomed cylindrical member 2. From there, attenuator 1
In order to prevent vibrations from being transmitted to the piston rod 1b, it is preferable that the piston rod 1b has a sufficiently small spring constant in the axial direction, as described above.

Furthermore, this elastic member 11 has a degree of freedom in design since it does not need to have a sealing function.
The spring constant of the piston rod 1b can be made sufficiently high in the radial direction, so that the swinging motion of the damper 1 relative to the bottomed cylindrical member 2 can be sufficiently restrained.

And here, further, on the outer periphery of the reduced diameter part 2c,
A mounting bracket 13 is connected via a cushioning material 12 having an appropriately selected spring constant.

According to the vibration isolating device configured in this way, when it is applied to a car, for example, the vehicle height can be adjusted by supplying and discharging compressed air to the air chamber 4.
Further, absorption of low frequency, small amplitude vibrations and large amplitude vibrations is performed in the same manner as in the prior art, respectively, by the viscous resistance of the liquid in the damper 1 and the volume change of the compressed air in the air chamber.

For example, if high-frequency vibrations are transmitted to the damper 1 connected to the axle side, the piston rod 1b will hardly vibrate, and the piston rod 1b will be at a frequency and vibration approximately equal to the input vibration to the cylinder 1a. It vibrates. Therefore, the piston rod 1b vibrates relative to the bottomed cylindrical member 2 in its axial direction, but this relative vibration is suppressed by the elastic member 11 having a small spring constant in the axial direction of the piston rod 1b. Since the vibration is allowed under small resistance, the vibration is sufficiently insulated from the bottomed cylinder member 2 and the vehicle body side. Note that, on the other hand, the cylinder 1a
The high-frequency vibrations transmitted to the cylindrical membrane 3 are also transmitted to the cylindrical cantilevered membrane 3, but some of it is due to a change in the volume of the compressed air in the air chamber 4, and the rest is transmitted to the cushioning material 12.
Since the vibration is absorbed by the elastic deformation of the vibration, transmission of the vibration to the vehicle body side is effectively prevented.

In addition, when a force in the swinging direction with respect to the bottomed cylinder member 2 acts on the damper 1, the piston rod 1b
An elastic member 1 having a large spring constant in the radial direction of
1 can advantageously restrain the rocking motion of the damper 1, so that the cylinder 1a or the cylindrical encasing membrane 3 collides with the bottomed cylindrical member 2, which reduces the vibration absorption performance of the damper 1 and reduces the durability of the device. This will eliminate inconveniences such as a decrease in Furthermore, as a result of the advantageous restraint of the rocking motion of the damper 1 here, even if a rocking motion occurs in the bottomed cylindrical member 2 in conjunction with the damper 1, it will be absorbed by the buffer material 12. , it is not transmitted to the vehicle body.

Furthermore, the shock absorbing material 12 whose spring constant is appropriately selected is such that the angular motion input to the cylinder 1a about its axis due to, for example, steering of an automobile passes through the cylindrical canopy membrane 3 to the bottomed cylindrical member. Even if the angular movement is transmitted to the vehicle body, the angular motion is not transmitted to the vehicle body.

FIG. 4 is a sectional view of a main part showing another embodiment of the present invention. In this example, the reduced diameter portion 2 of the bottomed cylindrical member 2 is
c is separated from other parts by a stopper 14 through which the piston rod 1b passes, and a flange 15 provided at the end of the piston rod 1b within the reduced diameter portion 2c.
, a ring-shaped or circumferentially interrupted rubber or rubber-like elastic member 1 having a substantially rhombic cross-sectional shape;
6 is fixed without being connected to the reduced diameter portion 2c.
The elastic member 16 here eliminates the need to connect the piston rod 1b and the bottomed cylindrical member 2, and the degree of freedom in design for the required spring constant is further increased, so that the elastic member 16 is more flexible than the elastic member 11 in the above-described embodiment. It can exhibit excellent vibration isolation and rocking restraint functions.

In this example, the relative vibration of the piston rod 1b with respect to the bottomed cylindrical member 2 is allowed under the guidance of the elastic member 16 and the peripheral wall of the reduced diameter portion 2c.
Further, the swinging movement of the damper 1 relative to the bottomed cylindrical member 2 is effectively restrained by the elastic member 16 and the stopper 14. Preferably, as shown in the figure, the elastic member 16 is moved between the bottom groove 2a of the reduced diameter portion 2c and the stopper 14 with which it comes into contact due to the above-described relative vibration of the piston rod 1b.
This reduces the deformation reaction force exerted on the bottomed cylindrical member 2 due to the deformation of the elastic member 16 based on the relative vibration of the piston rod 1b.

Although this invention has been explained above based on illustrated examples,
Similar effects can be achieved even if the directions of vibration and rocking motion are reversed. In addition, the shape, dimensions, spring constant of the elastic member 16 and the cushioning material 12,
Of course, the mounting position and the like can be changed as necessary.

Effects of the Invention Therefore, according to the present invention, an elastic member is disposed within the bottomed cylindrical member between it and the piston rod to insulate the relatively small relative movement of the piston rod in the axial direction with respect to the bottomed cylindrical member. This can sufficiently prevent vibrations from being transmitted from the piston rod to the bottomed cylindrical member and in the opposite direction, and can increase the spring constant of the elastic member in the radial direction of the piston rod as required. Relative rocking motion of the piston rod with respect to the bottomed cylindrical member can be effectively restrained. In addition, by connecting the mounting bracket to the outer periphery of the bottomed cylindrical member via a cushioning material, the angular movement and impulsive movement of the bottomed cylindrical member can be advantageously absorbed.

[Brief explanation of drawings]

1 and 2 are sectional views showing a conventional example, and FIGS. 3 and 4 are sectional views showing an embodiment of the present invention, respectively. 1...Attenuator, 1a...Cylinder, 1b...
Piston rod, 2...Bottomed cylindrical member, 2a...Bottom wall, 2c...Reduced diameter portion, 3...Cylindrical encasing membrane, 4...
Air chamber, 11, 16...Elastic member, 12...Buffer material, 13...Mounting bracket, 14...Stopper, 15...Flange.

Claims (1)

[Claims] 1 A telescope-type attenuator, a bottomed cylindrical member surrounding the piston rod of this attenuator, and a cylindrical flexible tube whose one end is airtightly connected to the cylinder of the attenuator and the other end to the bottomed cylindrical member. a diaphragm, an elastic member disposed between the piston rod and the bottomed cylindrical member to allow relative movement of the piston rod in the axial direction with respect to the bottomed cylindrical member, and a cushioning material provided on the outer periphery of the bottomed cylindrical member. A vibration isolator comprising a mounting bracket connected to the mounting bracket.